Discuss the main factors which led to the outbreak of the 2007-2009 Sub-Prime Mortgage Crisis in the US? Given the example about the Sub-prime crisis and Northern Rock, Please answer the following questions: What are the origins of the sub-prime crisis? How did this crisis impact on Northern Rock? What role did the Repo and the Inter-bank markets play in the crisis? How did the Government and the Bank of England act to save Northern Rock?